The invention relates to a method for determining the offset between conductor paths and contact holes in a conductor plate. The invention also relates to a conductor plate for use with this method.
In the reproduction of printed circuits for the electronics industry, components are inserted with their contact pins into a conductor plate and soldered there, so that a finished electronic circuit is obtained. To produce this type of conductor plate, conductor paths are applied onto plates made of electrically insulating material, using, for example, a galvanic method. At the places provided for the connecting pins of the components which are to be soldered-in, the conductor paths are usually widened to form contact eyes. In a further and separate operational step, the contact holes for the components which are to be inserted are bored or punched into the contact eyes at the intended locations. Application of the conductor paths and the punching or boring of the holes is thus not done in the same operational step, but at different times, one step following the other. As a result, offsetting can occur between the position of the actual punched contact holes and their ideal position on the conductor plate.
Considerable disadvantages are connected with such offsetting. For example, the contact hole may intercept and interrupt the minimum rim of the conductor path, so that there is no longer any assurance that, when a component is soldered-in, the pin of this component which is located in that contact hole is securely united by soldering with the contact eye of the conductor path. If the offset is very large, the contact hole may even be located outside the contact eye, and thus no conducting connection will be achieved by soldering between the component and the associated conductor path.
A further disadvantage of offsetting is that during the automatic application of the component parts to the conductor plate by the component machine, the connecting pins of the component to be inserted are lined up according to a component pattern which corresponds to the pattern of the conductor plate rather than to the pattern of the punched contact holes. As a result, when there is an offset between the conductor paths and the punched or bored contact holes, the connecting pins of the components may be inserted into the conductor plate adjacent rather than in the holes. This results in these connecting pins not being soldered together in the solder bath with the proper conductor path. Further, when a contact pin is mounted adjacent a contact hole, the contact pin may also become bent, so that the component is no longer suitable for automatic application.
There is, therefore, a need for a method with which the offset between conductor paths and contact holes in a conductor plate may be determined and taken into account.
One object of the present invention is to provide a method for determining the offset between conductor paths and contact holes in a conductor plate.
Another object is to provide a method for recognizing an offset in a conductor plate which exceeds the tolerance limits, so that such a conductor plate can be automatically eliminated in the manufacturing process.
Another object is to provide a conductor plate with which such methods may be carried out.
Other objects and advantages of the invention will appear from the following description.